Constnium/node_modules/eslint-visitor-keys/lib/index.js
2022-06-23 02:27:43 +02:00

65 lines
1.7 KiB
JavaScript

/**
* @author Toru Nagashima <https://github.com/mysticatea>
* See LICENSE file in root directory for full license.
*/
import KEYS from "./visitor-keys.js";
/**
* @typedef {{ readonly [type: string]: ReadonlyArray<string> }} VisitorKeys
*/
// List to ignore keys.
const KEY_BLACKLIST = new Set([
"parent",
"leadingComments",
"trailingComments"
]);
/**
* Check whether a given key should be used or not.
* @param {string} key The key to check.
* @returns {boolean} `true` if the key should be used.
*/
function filterKey(key) {
return !KEY_BLACKLIST.has(key) && key[0] !== "_";
}
/**
* Get visitor keys of a given node.
* @param {object} node The AST node to get keys.
* @returns {readonly string[]} Visitor keys of the node.
*/
export function getKeys(node) {
return Object.keys(node).filter(filterKey);
}
// Disable valid-jsdoc rule because it reports syntax error on the type of @returns.
// eslint-disable-next-line valid-jsdoc
/**
* Make the union set with `KEYS` and given keys.
* @param {VisitorKeys} additionalKeys The additional keys.
* @returns {VisitorKeys} The union set.
*/
export function unionWith(additionalKeys) {
const retv = /** @type {{
[type: string]: ReadonlyArray<string>
}} */ (Object.assign({}, KEYS));
for (const type of Object.keys(additionalKeys)) {
if (Object.prototype.hasOwnProperty.call(retv, type)) {
const keys = new Set(additionalKeys[type]);
for (const key of retv[type]) {
keys.add(key);
}
retv[type] = Object.freeze(Array.from(keys));
} else {
retv[type] = Object.freeze(Array.from(additionalKeys[type]));
}
}
return Object.freeze(retv);
}
export { KEYS };